Recycling of coal gangue in alpine mining areas: Mechanism of SAPs regulating the pore structure to improve water retention capacity and their optimizing effect

作者：Xiaozhan Wang, Zhilong Sun, Changqing Shi, Jie Yang, Chunyan Yang, Monan Deng, Cheng Li · 发表于：Environmental Technology & Innovation · 年份：2026 · DOI：10.1016/j.eti.2026.104779 · 被引用次数：2 · 研究领域：Polymer-Based Agricultural Enhancements、Climate change and permafrost、Freezing and Crystallization Processes

The Muli mining area suffers severe ecological damage, primarily due to unregulated mining in the early stage. Coal gangue, as the main waste in the mining area, is characterized by poor water retention capacity and rapid water evaporation, significantly limiting ecological restoration. To improve the water retention capacity of the coal gangue matrix, coal gangue collected from the Juhugeng mining area of Muli Coalfield in Qinghai Province is considered the research object in this study. The influence of superabsorbent polymers (SAPs) on the water retention capacity of coal gangue is systematically explored by constructing different particle size gradations and adding SAPs with a gradient mass fraction of 0–0.4%. With the aid of saturated water content (SWC), capillary water content (CWC), field capacity (FC), infiltration-evaporation dynamics, and freeze-thaw cycle experiments, the regulatory mechanism of water characteristics is analyzed using variance and multiple regression analysis. The results of this study show that: (1) Water retention capacity is synergistically regulated by multiple factors. It is positively correlated with SAP mass fraction and particle size gradation (where SWC increases by 12.10%), but negatively correlates with bulk density and the number of freeze-thaw cycles (where SWC decreases by 5.03%). SAPs improve water retention capacity by increasing capillary porosity, but at the cost of aeration. (2) SAPs play a vital role in inhibiting water loss: I...